Summer vacation! Seiji, Guri, Akane and Yuzu have invited Akua to go with them to the beach. Akane tries to get Akua to go swimming with her in attempt to get closer to Seiji's little sister, but Akua gives her the cold shoulder. Pouting at her brother and his harem Akua goes to swim by herself but a dark shadow looms beneath her. Meanwhile, summer also means tests of courage! Guri suddenly invites Seiji, Akane, and Yuzu to the school after dark for a test of courage but her real motives are to pair another young couple who have asked for her help. Seiji thinks something isn't quite right about the pair though...
Seiji et toute la clique enfilent leurs maillots de bain et vont à la plage. À leur retour, ils participent à un test de courage un peu particulier.
夏休み!青司、グリ、茜、柚はあくあを誘って海へ向かう。
あくあと仲良くなりたい茜は一緒に泳ごうと誘ってみるが、
彼女の態度は相変わらず冷たい。
そして夜は肝試し!だけどグリ主催の肝試しがただの肝試しな訳もなくて――。
Seiji, Akane, Yuzu, Guri e Akua vão para praia, e entre uma brincadeira e outra, o assistente de cupido fica sabendo mais da história das famílias das meninas.
Seiji y compañía irán a pasar un agradable día a la playa. Allí, entre muchas otras cosas, jugarán, nadarán en el mar... y pelearán.
Evviva, le vacanze estive! Akua accetta l'invito di Seiji ad andare al mare con lui, ma non si aspetta che non sarà una vacanza a due, ma a cinque! Con loro, infatti, ci sono anche Guri, Yuzu e Akane.